i. Technical Field
The present invention relates to stapling instruments and, in various embodiments, to a surgical stapling instrument for producing one or more rows of staples.
ii. Background of the Related Art
In recent years, there has been an increasing tendency for surgeons to use stapling instruments to suture body tissues such as a lung, an esophagus, a stomach, a duodenum and/or other organs in the intestinal tract. The use of an appropriate stapling instrument in many instances may perform a better job in less time and simplify previously difficult surgical procedures such as gastrointestinal anastomoses. Previous linear two and four row cutting staplers comprised cartridge-less instruments into which staples were individually hand-loaded. Other previous devices have included a presterilized disposable staple loading unit and a cutting member which could be utilized for dividing the tissue and forming the rows of staples simultaneously. An example of such a surgical stapler is disclosed in U.S. Pat. No. 3,499,591, entitled INSTRUMENT FOR PLACING LATERAL GASTROINTESTINAL ANASTOMOSES, which issued on Mar. 10, 1970, the entire disclosure of which is hereby incorporated by reference herein.
A stapling instrument can include a pair of cooperating elongate jaw members, wherein each jaw member can be adapted to be inserted into an internal, tubular body organ to be anastomosed. In various embodiments, one of the jaw members can support a staple cartridge with at least two laterally spaced rows of staples, and the other jaw member can support an anvil with staple-forming pockets aligned with the rows of staples in the staple cartridge. Generally, the stapling instrument can further include a pusher bar and knife blade which are slidable relative to the jaw members to sequentially eject staples from the staple cartridge via camming surfaces on the pusher bar. In at least one embodiment, the camming surfaces can be configured to activate a plurality of staple drivers carried by the cartridge and associated with the individual staples to push the staples against the anvil and form laterally spaced rows of deformed staples in the tissue gripped between the jaw members. In typical stapling instruments, however, the anvil is unmovable relative to the staple cartridge once the jaw members have been assembled together and the formed height of the staples cannot be adjusted. In at least one embodiment, the knife blade can trail the pusher bar and cut the tissue along a line between the staple rows. Examples of such stapling instruments are disclosed in U.S. Pat. No. 4,429,695, entitled SURGICAL INSTRUMENTS, which issued on Feb. 7, 1984, the entire disclosure of which is hereby incorporated by reference herein.
In various embodiments, a typical stapling instrument can include first and second jaw members which can be secured together by a latch, wherein the latch can be moved between an open position, a partially-closed position, and a closed position. In the open and partially-closed positions of the latch, however, the first and second jaw members of a typical stapling instrument can be unintentionally detached from each other, thereby requiring additional time to reassemble the jaw members. In certain circumstances, the detachment of the first and second jaw members may expose a knife blade. In various circumstances, further to the above, a stapling instrument can include an actuator knob extending from the pusher bar which can be configured to be grasped by a surgeon and advanced distally to advance the pusher bar and knife blade within the staple cartridge. In certain circumstances, however, the actuator knob can be advanced relative to a jaw member eventhough the first and second jaw members have not been assembled. Once assembled, in at least one circumstance, the actuator knob, as it can extend outwardly from the surgical instrument, can unintentionally contact tissue surrounding the surgical site and, as a result, the tissue may impede the advancement of the actuator knob. In such circumstances, a surgeon may have to force the actuator knob past the tissue and/or re-position the stapling instrument which can increase the time needed to complete the surgery. What is needed is an improvement over the foregoing.